Francis spoke on Saturday at the Vatican to an Italian Catholic anti-abortion group.
He praised their efforts but stressed that defending life also means assuring that people have health, education and job opportunities.
Francis encouraged politicians to defend the unborn for the common good, saying that the young bring hope and a future to society.
The pope decried "their killing in huge numbers" as undermining "the foundations of the construction of justice, compromising the proper solution of any other human and social issue".
Catholic teaching forbids abortion.
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